Method for active dry yeast rehydration and rehydration medium

Abstract

Method for rehydration active dry yeasts intended for alcoholic fermentation includes placing the active dry yeasts in an aqueous medium containing at least inactive yeasts or a yeast derivative, and optionally one or several complementary nutrients selected among sources of organic or inorganic nitrogen, vitamins, mineral salts, fatty acids, sterols, or natural sources rich in those elements. The invention also concerns the rehydrating media used in the method. The invention which enables to avoid fermentation problems is useful for producing wines and other fermented alcoholic drinks.

1 - 15 . (cancelled)  
     
     
         16 . Method of rehydrating active dry yeasts for alcoholic fermentation, characterised in that said active dry yeasts are placed in an aqueous medium containing inactive yeasts or a yeast derivative at a rate of 100 to 200 g/l, preferably 150 g per litre of medium.  
     
     
         17 . Method of rehydrating active dry yeasts according to  claim 16 , characterised in that said active dry yeasts are placed in an aqueous medium containing in addition one or more nutrients chosen from sources of organic or inorganic nitrogen, vitamins, mineral salts, fatty acids, sterols or natural sources rich in these elements.  
     
     
         18 . Method of rehydrating dry active yeasts according to  claim 17 , comprising essentially the steps consisting in: 
 a) preparing a rehydration medium comprising    i) inactive yeasts or a yeast derivative, at a rate of 100 to 200 g/l, preferably 150 g per litre of medium, and    ii) one or more nutrients chosen from ammonium salts, nitrates, urea, amino acids, peptides, proteins or a biological source rich in nitrogen; a fatty acid, a sterol, a combination of these or a natural source rich in these elements such as especially mud: thiamine, biotin, pantothenic acid, niacin, riboflavin, pyridoxine, or a natural source rich in vitamins; phosphates, salts of: zinc, magnesium, calcium, potassium, sodium, iron, copper, manganese or a combination of these mineral salts, each selected nutrient being added at a concentration which is 200 to 1000 times greater, preferably 500 times greater than that which it will have in the must to be fermented, in an aqueous medium, preferably glucose water or grape juice,    b) introducing the active dry yeasts into the rehydration medium thus prepared at a rate of 50 to 150 g/l, preferably 100 g per litre of medium;    c) incubating the rehydration medium containing the active dry yeasts at a temperature of between 30° C. and 45° C., preferably 37° C., for 20 to 40 minutes, preferably 30 minutes.    
     
     
         19 . Method of rehydrating active dry yeasts according to  claim 18  comprising essentially the steps consisting in: 
 a) preparing a rehydration medium comprising,  
 i) inactive yeasts or a yeast derivative at a rate of 100 to 200 g/l, preferably 150 g per litre of medium, and  
 ii) one or more of the following constituents: 20 to 50 mg/l of calcium pantothenate, 0.15 to 0.30 mg/l of biotin, 20 to 60 mg/l of zinc salt, 200 to 500 mg/l of magnesium salt, 2 to 5 mg/l of manganese salt, in an aqueous medium, preferably glucose water or grape juice;  
 b) introducing the active dry yeasts into the rehydration medium thus prepared at a rate of 50 to 150 g/l, preferably 100 g per litre of medium;  
 c) incubating the rehydration medium containing the active dry yeasts at a temperature of between 30° C. and 45° C., preferably 37° C., for 20 to 40 minutes, preferably 30 minutes.  
 
     
     
         20 . Rehydration medium for active dry yeasts, comprising at least, in an aqueous medium which is or is not sugary, inactive yeasts or a yeast derivative at a rate of 100 to 200 g/l, preferably 150 g per litre of medium.  
     
     
         21 . Rehydration medium according to  claim 20 , comprising at least, in an aqueous medium which is or is not sugary, 
 i) inactive yeasts or a yeast derivative, at the rate of 100 to 200 g/l, preferably 150 g per litre of medium,    ii) one or more nutrients chosen from ammonium salts, nitrates, urea, amino acids, peptides, proteins or a biological source rich in nitrogen; a fatty acid, a sterol, a combination of these or a natural source rich in these elements such as especially mud: thiamine, biotin, pantothenic acid, niacin, riboflavin, pyridoxine, or a natural source rich in vitamins; phosphates, salts of: zinc, magnesium, calcium, potassium, sodium, iron, copper, manganese or a combination of these mineral salts, at a concentration which is 200 to 1000 times greater, preferably 500 times greater than that which it will have in the must to be fermented.    
     
     
         22 . Rehydration medium for active dry yeasts according to  claim 21 , comprising at least, in an aqueous medium, preferably water with glucose added at a rate of 50 g/l, or grape juice, 
 i) inactive yeasts or yeast extracts, at the rate of 100 to 200 g/l, preferably 150 g/l,    ii) one or more of the following constituents: 27 mg/l of calcium pantothenate, 0.2 mg/l of biotin, 50 mg/l of zinc salt, 433 mg/l of magnesium salt, 4 mg/l of manganese salt.    
     
     
         23 . Dry composition intended for the preparation of a rehydration medium for active dry yeasts according to  claim 20 , characterised in that it comprises at least 
 i) at least 98% by weight of inactive yeasts or of yeast derivative, in dehydrated form,    ii) one or more nutrients chosen from ammonium salts, nitrates, urea, amino acids, peptides, proteins or a biological source rich in nitrogen; a fatty acid, a sterol, a combination of these or a natural source rich in these elements such as especially mud: thiamine, biotin, pantothenic acid, niacin, riboflavin, pyridoxine, or a natural source rich in vitamins; phosphates, salts of: zinc, magnesium, calcium, potassium, sodium, iron, copper, manganese or a combination of these mineral salts.    
     
     
         24 . Dry composition intended for the preparation of a rehydration medium for active dry yeasts according to  claim 21 , characterized in that it comprises at least 
 i) at least 98% by weight of inactive yeasts or of yeast derivative, in dehydrated form,    ii) one or more nutrients chosen from ammonium salts, nitrates, urea, amino acids, peptides, proteins or a biological source rich in nitrogen; a fatty acid, a sterol, a combination of these or a natural source rich in these elements such as especially mud: thiamine, biotin, pantothenic acid, niacin, riboflavin, pyridoxine, or a natural source rich in vitamins; phosphates, salts of: zinc, magnesium, calcium, potassium, sodium, iron, copper, manganese or a combination of these mineral salts.    
     
     
         25 . Dry composition intended for the preparation of a rehydration medium for active dry yeasts according to  claim 22 , characterized in that it comprises at least 
 i) at least 98% by weight of inactive yeasts or of yeast derivative, in dehydrated form,    ii) one or more nutrients chosen from ammonium salts, nitrates, urea, amino acids, peptides, proteins or a biological source rich in nitrogen; a fatty acid, a sterol, a combination of these or a natural source rich in these elements such as especially mud: thiamine, biotin, pantothenic acid, niacin, riboflavin, pyridoxine, or a natural source rich in vitamins; phosphates, salts of:    zinc, magnesium, calcium, potassium, sodium, iron, copper, manganese or a combination of these mineral salts.    
     
     
         26 . Dry composition according to  claim 23 , characterised in that it comprises at least 
 i) about 99.3% by weight of inactive yeasts or yeast extract, in dehydrated form,    ii) one or more nutrients chosen from pantothenic acid, biotin, a zinc salt, a magnesium salt, a manganese salt.    
     
     
         27 . Method of producing a fermented alcoholic drink, characterised in that the must is cultured by yeasts prepared by a method according to  claim 16 .  
     
     
         28 . Method of producing a fermented alcoholic drink, characterized in that the must is cultured by yeasts rehydrated in a medium according to  claim 20 .  
     
     
         29 . Method of producing a fermented alcoholic drink, characterized in that the must is cultured by yeasts rehydrated in a medium according to  claim 21 .  
     
     
         30 . Method of producing a fermented alcoholic drink, characterised in that the must is cultured by yeasts rehydrated in a medium according to  claim 22 .  
     
     
         31 . Method of producing a fermented alcoholic drink according to  claim 27 , characterised in that the must is a grape juice.  
     
     
         32 . Fermented alcoholic drink obtained by a method according to  claim 27.